Seat belt retractor system

ABSTRACT

A vehicle seat belt retractor system (10) includes two seats (16, 18) each having its own integrated seat belt webbing retractor (60, 112). Each retractor (60, 112) includes a locking assembly (76, 80) for blocking belt withdrawal in response to an electrical signal. At a central location in the vehicle spaced from the seats (16, 18), a sensor (24) is disposed for sensing vehicle deceleration exceeding a predetermined deceleration and for providing a control signal indicative thereof. An RF transmitter (42) is electrically connected with the sensor (24) and is actuatable in response to the control signal to transmit an RF signal. An RF receiver (100, 114) on each vehicle seat (16, 18) receives the RF signal and provides an output signal to actuate the locking assembly (76, 80) of the two seat belt retractors (60, 112). Each vehicle seat (16, 18) also has (a) a battery (98) for supplying electric power to actuate the locking assembly (76, 80) of the retractors (60, 112) and (b) a piezoelectric member (90) responsive to an occupant sitting on the seat for generating an electric current to charge the battery (96). In a second embodiment, a separate deceleration sensor (24a) is mounted on each vehicle seat for electrically actuating its associated retractor. In a third embodiment, the transmitted signal provides the power for actuating a vehicle occupant restraint (178).

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a vehicle seat belt retractor systemwhich includes one or more electrically lockable seat belt retractorsintegrated into one or more vehicle seats.

2. Description of the Prior Art

It is known to provide a vehicle seat belt system integrated into avehicle seat. In such integrated systems, a seat belt retractor may belocated in the upper corner of the seat back. Seat belt webbing is woundon a spool in the retractor and extends from the retractor. In the eventof vehicle deceleration exceeding a predetermined deceleration, alocking mechanism in the retractor blocks rotation of the retractorspool in the belt withdrawal direction to restrain movement of thevehicle occupant.

SUMMARY OF THE INVENTION

The present invention relates to a vehicle occupant restraint systemintegrated into one or more vehicle seats. In a first embodiment of theinvention, a vehicle safety apparatus includes a seat having anintegrated seat belt webbing retractor. The retractor includes lockingmeans for blocking belt withdrawal in response to an electrical signal.

At a location in the vehicle, spaced from the seat, a sensor is disposedfor sensing vehicle deceleration exceeding a predetermined decelerationand for providing a control signal indicative of such deceleration. Aradio frequency (RF) transmitter powered by the vehicle's electricalsystem is electrically connected with the sensor and is actuatable inresponse to the control signal to transmit an RF signal. An RF receiveron the vehicle seat receives the RF signal and provides an electricalsignal to actuate the locking means of the seat belt retractor to lockthe retractor.

The vehicle seat includes an electrical energy storage device such as abattery for supplying electric power to actuate the locking means of theretractor. On the seat is an electrical energy generating device such asa piezoelectric member responsive to an occupant sitting on the seat forgenerating an electric current. The piezoelectric member charges thebattery with the electric current generated by the piezoelectric member.Thus, the portions of the seat belt system integrated into the seat donot require connection to the vehicle's electrical system.

A second vehicle seat may be provided with its own integrated seat beltretractor with locking means. A second RF receiver on the second vehicleseat simultaneously receives the RF signal and actuates the lockingmeans of the second retractor to lock the second retractor. A battery onthe second seat supplies electric power to actuate the locking means ofthe second retractor. A piezoelectric member on the second seat isresponsive to an occupant sitting on the second seat for generating anelectric current to charge the second battery.

A second embodiment of the invention does not include the RF transmitteror receiver or the deceleration sensor spaced from the vehicle seat.Instead, a separate deceleration sensor is mounted on each vehicle seatfor electrically actuating its associated retractor. Thus, no part ofthe seat belt system is powered by the vehicle's electrical system.

In a third embodiment of the invention, the energy contained in atransmitted radio signal is used to power a vehicle occupant protectiondevice. No other power source such as a battery or a vehicle electricalsystem is needed. Accordingly, a vehicle occupant protection device canbe integrated in a removable vehicle seat without the need to provide abattery in the seat or to provide electrical power connections betweenthe removable seat and the vehicle electrical system.

The retractors described herein can also include a redundant webbingsensitive device that will function to block rotation of the spool ineither a series or a parallel mechanism arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will becomeapparent to one skilled in the art to which the present inventionrelates upon consideration of the following description of the inventionwith reference to the accompanying drawings, wherein:

FIG. 1 is a fragmentary schematic view of a vehicle including a seatbelt retractor system constructed in accordance with the presentinvention;

FIG. 2 illustrates schematically a central crash sensor module of theretractor system of FIG. 1;

FIG. 3 is a schematic sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a pictorial view of a vehicle seat including portions of theseat belt retractor system of FIG. 1;

FIG. 5 is a block diagram of a control module located in the seat ofFIG. 4;

FIG. 6 is a view, partially in section, of a seat belt retractorincluding an electrically actuatable locking mechanism as used in theseat of FIG. 4;

FIG. 7 is a block diagram similar to FIG. 5 of a control module inaccordance with a second embodiment of the invention;

FIG. 8 is a view similar to FIG. 1 including a vehicle safety apparatusin accordance with a third embodiment of the invention;

FIG. 9 is a schematic illustration of electric circuitry in the vehiclesafety apparatus of FIG. 8;

FIG. 10 is a schematic view of a portion of the vehicle safety apparatusof FIG. 8; and

FIG. 11 is a view similar to FIG. 6 of a seat belt retractor forming apart of the vehicle safety apparatus of FIG. 8.

DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

The present invention relates to a vehicle seat belt system andparticularly to a seat belt system integrated into one or more vehicleseats. The present invention is applicable to various seat belt systems.As representative of the present invention, FIG. 1 illustratesschematically a seat belt system 10.

The seat belt system 10 is incorporated in a vehicle 12. The vehicle 12includes a load bearing body or frame structure 14. First and secondvehicle occupant seats 16 and 18 are supported on the vehicle structure14.

A central crash sensor and transmitter module 20 is rigidly mounted tothe vehicle structure 14. The central module 20 is mounted to thestructure 14 at a location spaced apart from the seats 16 and 18,preferably at or near the center of gravity of the vehicle. The centralmodule 20, as illustrated schematically in FIGS. 2 and 3, includes asupport member 22 which is electrically non-conductive. A decelerationsensor switch 24 is connected with the support member 22.

The deceleration sensor switch 24 includes a hollow conical member 26made of an electrically conductive material, preferably metal. Theconical member 26 is suspended from the support member 22. An inertiamass 28, which is preferably a metal ball, is supported for rollingmovement on the inside of the conical member 26. An electricallyconductive pad 30 is disposed within the conical member 26, on theunderside of the support member 22. The conductive pad 30 is spacedapart from the conductive conical member 26.

The conductive pad 30 is connected by electrical wiring 36 to thevehicle battery 38 which is part of the electrical system of the vehicle12. The conical member 26 is connected by electrical wiring 40 to an RFtransmitter 42 mounted on the support member 22.

The first vehicle seat 16 (FIG. 4) includes a frame 50, a seat bottomcushion 52, and a seat back 54. A length of seat belt webbing 56,connected with the seat 16, is extensible around an occupant of the seatto restrain movement of the occupant.

The seat belt webbing 56 extends through a retractor 60 (FIG. 6) whichis similar to the retractor shown in U.S. Pat. No. 4,895,317. In theretractor 60, the belt webbing 56 is wound around a retractor spool 62rotatable in a housing 64 in a belt retraction direction 66 and anopposite belt withdrawal direction 68.

The retractor 60 includes an actuator lever 70 movable into engagementwith one of a plurality of ratchet teeth 71 on the outer periphery of aclutch disk 72. The clutch disk 72 is part of an intermediate linkagefor blocking rotation of the spool 62 in the belt withdrawal direction68 upon movement of the actuator lever 70 into a position in engagementwith the clutch disk. The clutch disk 72 is supported for rotation aboutthe axis 73 of the retractor 60. A pin 74 projects axially from theclutch disk 72.

The retractor 60 also includes a drum 75 connected for rotation with thespool 62. A pilot pawl 76 is rotatable with the drum 75 and is supportedfor pivotal movement on the drum. The pilot pawl 76 has first and secondend portions 77 and 78.

The second end portion 78 of the pilot pawl 76 is engageable with one ofa plurality of ratchet teeth 79 formed on the inner periphery of a ring81 which is supported for rotation about the axis 73. The ring 81 isformed as a part of, or otherwise connected for rotation with, anactuator member 83 engageable with a lock pawl (not shown). The lockpawl is engageable with a ratchet wheel (also not shown) connected forrotation with the retractor spool 62.

The retractor 60 includes an electromagnet assembly 80 which includes acoil 82. The coil 82 is energizeable, by electric current flowingthrough wiring 84, to move the actuator lever 70 into engagement withthe clutch disk 72.

The first vehicle seat 16 (FIG. 1) also includes a battery charger unit90 disposed in the seat bottom cushion 52. The battery charger unit 90includes a known flexible piezoelectric film which, when deformed,generates an electric current.

The piezoelectric charger unit 90 is connected by wiring 92 to a controlmodule 94 (FIG. 5) fixed to the seat frame 50. The control module 94includes a battery 96. The battery 96 is preferably a known batterywhich has a six-volt output and a ten year life. A battery with adifferent voltage, such as three volts, may also be used.

The output of the battery 96 (FIG. 5) is connected to a capacitor andvoltage booster assembly 98. The output of the assembly 98 is connectedto an RF receiver switch 100. The RF receiver switch 100 includes an RFreceiver for receiving a signal from the RF transmitter 42 (FIG. 2). TheRF receiver switch 100 also includes a switch for connecting theassembly 98 to retractor lock and timer circuitry indicatedschematically at 102.

The second vehicle seat 18 (FIG. 1) is similar to the first seat 16. Thesecond seat 18 includes a length of seat belt webbing 110 associatedwith a seat belt webbing retractor 112. The retractor 112 is similar tothe retractor 60, and includes a similar electrically actuatable lockingassembly for blocking withdrawal of the belt webbing 110 from theretractor 112. The locking assembly of the retractor 112 is actuatableby a control signal generated by a control module 114 similar to thecontrol module 94 of the first seat 16. The control module 114 islocated in the second seat 18.

During normal operation of the vehicle 12, whenever a vehicle occupantsits on the seat bottom cushion 52 (FIG. 4), the weight of the vehicleoccupant deforms the piezoelectric film in the battery charger unit 90.When the piezoelectric film deforms, it generates an electric currentwhich passes through the wires 92 to the battery 96. The electriccurrent maintains the battery 96 in a charged condition havingsufficient power to supply the remaining components of the controlmodule 94 as well as the electromagnet assembly 80.

In the event of vehicle deceleration exceeding a predetermineddeceleration, such as occurs in a collision, the metal ball 28 of thedeceleration sensor switch 24 moves along the inclined surface of theconical member 26 into engagement with the conductive pad 30. Theengagement of the metal ball 28 with the conductive pad 30 completes anelectric circuit between the conical member 26 and the conductive pad30. Completion of this circuit enables current to flow from the vehiclebattery 38 through the deceleration sensor switch 24 and to the RFtransmitter 42.

The RF transmitter 42 when thus energized transmits an RF signal withinthe vehicle 12. The RF signal is received by the RF receiver switch 100of the first seat control module 94. Reception of the RF signal resultsin closing of the switch within the RF receiver switch 100, toelectrically connect the output of the assembly 98 to the retractor lockand timer circuitry 102.

The retractor lock and timer circuitry 102 applies an electric currentover the wiring 84 to the coil 82 of the electromagnet assembly 80 inthe retractor 60. The electromagnet assembly 80 moves the actuator lever70 into engagement with one of the teeth 71 on the clutch disk 72. Theengagement of the actuator lever 70 with the ratchet tooth 71 blocksrotation of the clutch disk 72 in the belt withdrawal direction 68.

Upon subsequent or continued withdrawal of belt webbing 56 from theretractor 60, the drum 75, which is connected for rotation with thespool 62, rotates in the belt withdrawal direction 68 relative to thestationary clutch disk 72. The relative rotation between the drum 75 andthe clutch disk 72 causes the first end portion 77 of the pilot pawl 76to engage the pin 74 on the clutch disk 72.

The engagement of the pin 74 with the pilot pawl end portion 77 causesthe pilot pawl 76 to pivot from the position shown in FIG. 6 to aposition (not shown) in which the second end portion 78 of the pilotpawl engages one of the ratchet teeth 79 on the ring 81. The pilot pawl76 transmits the force of the rotating drum 75 and spool 62 to the ring81, causing the ring to rotate about the axis 73.

Rotation of the ring 81 causes the actuator member 83 to rotate and tomove the lock pawl (not shown) into engagement with the ratchet wheel(not shown). The engagement of the lock pawl with the ratchet wheelblocks rotation of the spool 62 in the belt withdrawal direction 68.This blocks withdrawal of belt webbing 56 from the retractor 60, thusrestraining the vehicle occupant.

The battery 96 in the first seat 16 has an output of about six volts.The capacitor and voltage booster assembly 98 acts to provideapproximately 30 volts of power to the retractor coil 82 for about tenmilliseconds, and then decays to the normal battery voltage of sixvolts. The 30 volt pulse applied to the electromagnet assembly 80 movesthe actuator lever 70 more rapidly into engagement with the clutch disk72 than if only the six volt output of the battery 96 were applied.

The retractor lock and timer circuitry 102 keeps the electromagnetassembly 80 energized for about 100 milliseconds. Thus, the actuatorlever 70 is held in engagement with the clutch disk 72 for about 100milliseconds, even if the deceleration sensor switch 24 is actuated fora shorter period of time. After the 100 millisecond period, if thedeceleration sensor switch 24 is still closed, the retractor lock andtimer circuitry 102 maintains the retractor 60 in the locked condition.

Upon cessation of vehicle deceleration exceeding the predetermineddeceleration, the metal ball 28 moves away from the conductive pad 30,thereby de-energizing the RF transmitter 42. The RF transmitter 42ceases transmission of its RF signal, and the RF receiver switch 100opens, deactivating the electromagnet assembly 80. The actuator lever 70disengages from the clutch disk 72, enabling rotation of the spool 62 inthe belt withdrawal direction 68.

At the same time as the RF signal from the RF transmitter 42 is beingreceived by the RF receiver switch 100 in the first seat 16, the RFsignal is also being received by an RF receiver switch in the controlmodule 114 of the second vehicle seat 18. The second seat control module114 then actuates the locking mechanism of the second seat retractor112. The second seat retractor 112 blocks withdrawal of the belt webbing110 from the second seat retractor, thus restraining movement of thevehicle occupant in the seat 18. Thus, the retractor 112 of the secondvehicle seat 18 is locked simultaneously with the locking of theretractor 60 of the first seat 16.

As noted above, the control module 94 in the vehicle seat 16 does notinclude a deceleration sensor. Therefore, the control module 94 can bemounted in any location and in any orientation in the vehicle seat 16.The control module 94 can, for example, be connected with the retractor60 in a tiltable vehicle seat back.

Further, all electrical parts of the system 10 which are on or in theseat 16 are powered by the battery 96, which is also in the seat 16.Thus, the seat 16 may be removed entirely from the vehicle withoutneeding to be disconnected from the electrical system of the vehicle 12.

Any suitable number of vehicle occupant safety devices can besimultaneously actuated by the RF signal transmitted from the RFtransmitter 42. Thus, if more than two seats are provided in a vehicle,each with its own electrically actuatable seat belt retractor, all ofthe retractors can simultaneously be actuated by the one single centraldeceleration sensor and transmitter module 20.

FIG. 7 illustrates a seat control module 120 which is part of a seatbelt retractor system in accordance with a second embodiment of theinvention. In the second embodiment, parts which are similar to those ofthe first embodiment are given the same reference number with the suffix"a" added. The seat belt retractor system including the module 120 doesnot include a central deceleration sensor and transmitter module 20.Instead, the seat-mounted control module 120 includes, in place of theRF receiver switch 100 (FIG. 5), a deceleration sensor switch 24a whichis similar to the deceleration sensor switch 24 (FIG. 3). The controlmodule 120 is otherwise similar to the control module 94. The controlmodule 120 is disposed in a non-tiltable portion of a vehicle seat. Thecontrol module 120 is electrically connected with a retractor such asthe retractor 60.

In the event of vehicle deceleration exceeding a predetermineddeceleration, the deceleration sensor switch 24a in the seat-mountedcontrol module 120 completes an electric circuit including a battery96a, a capacitor and voltage booster assembly 98a, and retractor lockand timer circuitry 102a. The coil 82 of the electromagnet assembly 80in the retractor 60 is energized by an electric current transmitted fromthe control module 120 to block rotation of the retractor spool in thebelt withdrawal direction. This restrains movement of the vehicleoccupant in the seat which includes the control module 120.

With this second embodiment of the invention, the entire seat beltretractor system, including the deceleration sensor 24a, is completelyintegrated into the vehicle seat and is independent of the vehicle'selectrical system.

FIGS. 8-11 illustrate a vehicle safety apparatus 121 in accordance witha third embodiment of the invention. As shown in FIG. 8, a vehicle 122includes first and second vehicle seats 124 and 126. The seats 124 and126 are mounted on a body or other structure 128 of the vehicle 122.

A deceleration sensor 130 is mounted on the vehicle body 128 along witha transmitter 132. The sensor 130 and transmitter 132 may be of the typeillustrated in FIG. 2. The output of the transmitter 132 is coupled bysuitable electric wiring 134 to a windshield mounted antenna 136. Theantenna 136 is operative to transmit the output of the transmitter 132as an electromagnetic field (EMF) signal within the vehicle 122. Theantenna 136 can alternatively be mounted on the interior of the vehicleroof or head liner.

The vehicle seat 124 includes a vehicle occupant restraint 140. Thevehicle seat 126 includes a vehicle occupant restraint 142, identical tothe vehicle occupant restraint 140. In a preferred embodiment of theinvention, the vehicle occupant restraints 140 and 142 are vehicle seatbelt systems which include seat belt retractors similar to the retractor60 illustrated in FIG. 6, but without the electromagnet assembly 80.

The vehicle occupant restraint 140 includes a receiving antenna 144(FIG. 9) connected through a rectifying diode 146 to an LC tank circuit147. The LC tank circuit 147 includes an inductor which is a coil 148and a capacitor 150. The coil 148 and the capacitor 150 are wired inparallel. The ("LC") tank circuit 147 is grounded to the vehicle body128. The values of the coil 148 and of the capacitor 150 are selected sothat the tank circuit 147 resonates when it receives a signal with apredetermined frequency which is equal to the frequency of the EMFsignal transmitted by the transmitter 132. A frequency of transmissionof 200 MHz is preferably used.

The coil 148 (FIG. 10) is wound on a soft iron core 152. The coil 148 isdisposed between the poles 166 and 168 of a fixed permanent magnet 170.The coil 148 is fixed for rotation with a shaft 154 supported forrotational movement about an axis 156 on bearings 158 and 160. Suitableslip rings (not shown) provide the electrical connections to the movablecoil 148. Restraining springs 162 and 164 bias the coil 148 and theshaft 154 to a predetermined position of rotation relative to the axis156.

The shaft 154 is fixed for movement with an actuator lever 172 of a seatbelt retractor 178 (FIG. 11). The actuator lever 172 is movable, uponrotation of the shaft 154, between a first position resting on a stop174 and a second position in engagement with a clutch disk 176. Theretractor 178 includes a spool (not shown) on which belt webbing 180 iswound. The spool is rotatable in a belt withdrawal direction 182 and inan opposite belt retraction direction 184.

In the event of vehicle deceleration exceeding a predetermineddeceleration, such as occurs in a vehicle collision, the decelerationsensor 130 energizes the transmitter 132. The transmitter 132, whenenergized, causes the antenna 136 to transmit an EMF signal within thevehicle.

The EMF signal is received by the antenna 144 (FIG. 9) of the vehicleoccupant restraint 140. The EMF signal passes through the rectifyingdiode 146 to the tank circuit 147. The tank circuit 147 produces anoscillating current due to the tank circuit and a direct current in thecoil 148 due to the diode rectification. Because of the orientation ofthe coil 148 relative to the permanent magnet 170, the flow of directcurrent within the coil causes the coil to rotate about the axis 156,against the bias of the restraining springs 162 and 164.

As the coil 148 rotates about the axis 156, the shaft 154, which isfixed for rotation with the coil 148, rotates also. Rotation of theshaft 154 effects pivoting movement of the actuator lever 172 into itssecond position in engagement with the clutch disk 176. The actuatorlever 172 blocks rotation of the clutch disk 176 in the belt withdrawaldirection 182. As described above, this blocks rotation of the beltspool in the belt withdrawal direction 182 and therefore blockswithdrawal of belt webbing 180 from the retractor 178.

At the same time as the vehicle occupant restraint 140 is actuated bythe EMF signal from the transmitter 132, the vehicle occupant restraint142 is simultaneously actuated by the EMF signal. Actuation of thevehicle occupant restraint 142 occurs in a manner similar to the mannerof actuation of the vehicle occupant restraint 140, including locking ofa retractor 190 having an associated length of belt webbing 192.

The power to energize the coil 148 and to move the actuator lever 172 iscontained in and provided by the transmitted electromagnetic fieldsignal. The electric circuitry shown schematically in FIG. 10 extractsthe needed energy from the EMF signal to move the pawl 172. Assuming astatic magnetic field of 0.7 Tesla, 100 turns of wire in the coil 148, acoil length of 14 millimeters and radius of 7 millimeters, and a currentof 1 milliampere, a torque of 13.72 microjoules is produced to move theactuator lever 172.

The static magnetic field strength of 0.7 Tesla is available in aneodymium-iron combination permanent magnet. The 1 milliampere value isobtained by a transmitting antenna 136 producing a field of 10 volts permeter. At 6 meters, the field strength would be approximately 0.3 volts.This field will produce the 1 milliampere current in the tank circuit147.

The vehicle safety apparatus 121 eliminates the need for a separatepower source to actuate a vehicle occupant restraint mounted on avehicle seat. No battery is needed in either vehicle seat 124 or 126.Thus, no electrical connections are needed between the vehicle seats 124and 126 and the electrical circuitry of the vehicle 122. Accordingly,the vehicle safety apparatus 121 may be termed wireless. This allows theseats 124 and 126 to be easily removed from the vehicle 122 without theneed for disconnecting wiring harnesses, and no reconnection isnecessary when a vehicle seat is replaced.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications in the invention.For example, a different type of deceleration sensor switch could beused, such as a non-mechanical sensor. This could allow placement of thenon-mechanical deceleration sensor switch in a tiltable vehicle seatback along with a seat back angle sensor to compensate for the seat backinclination. Also, a different type of electrically actuatable retractorlocking mechanism could be used.

The system could additionally or alternatively incorporate a type ofactuatable vehicle safety device other than a seat belt retractor suchas a seat belt pretensioner, an inflatable seat belt, or an air bag.Such improvements, changes and modifications within the skill of the artare intended to be covered by the appended claims.

We claim:
 1. A vehicle safety apparatus comprising:a first seat for anoccupant of a vehicle; a first seat belt retractor having a first spoolon which belt webbing is wound and which is rotatable in a first beltwithdrawal direction and in an opposite first belt retraction directionand a first locking means for blocking belt webbing withdrawal from saidfirst spool in response to an electrical signal; mounting means formounting said first seat belt retractor on said first vehicle seat;sensor means for sensing vehicle deceleration exceeding a predetermineddeceleration and for providing a control signal indicative thereof; anRF transmitter electrically connected with said sensor means andactuatable in response to the control signal to transmit an RF signal;and first RF receiver means for receiving the RF signal and forproviding a first output signal indicative of the RF signal, said firstlocking means of said first seat belt retractor including meansactuatable in response to the first output signal for locking said firstseat belt retractor.
 2. A vehicle safety apparatus as set forth in claim1 wherein said first locking means comprises:a locking member movablebetween a first position in which said first spool is free to rotate inthe first belt withdrawal direction and a second position in which saidfirst spool is blocked from rotation in the first belt withdrawaldirection; and electromagnet means disposed adjacent to said lockingmember and electrically connected with said first RF receiver means andenergizeable in response to the first output signal for moving saidlocking member between its first and second positions.
 3. A vehiclesafety apparatus as set forth in claim 2 comprising an intermediatelinkage operatively disposed between said locking member and saidretractor spool, said locking member acting through said intermediatelinkage to block rotation of said spool in the belt withdrawal directionupon movement of said locking member into the second position.
 4. Avehicle safety apparatus as set forth in claim 1 comprising:a secondseat for an occupant of the vehicle; a second seat belt retractor havinga second spool on which belt webbing is wound and which is rotatable ina second belt withdrawal direction and in an opposite second beltretraction direction and a second locking means for blocking beltwebbing withdrawal from said second spool in response to an electricalsignal; mounting means for mounting said second seat belt retractor onsaid second vehicle seat; and second RF receiver means for receiving theRF signal and for providing a second output signal indicative of the RFsignal, said second locking means of said second seat belt retractorincluding means actuatable in response to the second output signal forlocking said second seat belt retractor.
 5. A vehicle safety apparatusas set forth in claim 4 wherein said sensor means for sensing vehicledeceleration is connected with the vehicle at a location spaced apartfrom said first seat and from said second seat.
 6. A vehicle safetyapparatus as set forth in claim 5 wherein said RF transmitter isdisposed at a location in the vehicle spaced apart from said first seatand from said second seat.
 7. A vehicle safety apparatus as set forth inclaim 4 wherein said first RF receiver means is mounted on said firstvehicle seat and said second RF receiver means is mounted on said secondvehicle seat.
 8. A vehicle safety apparatus as set forth in claim 7wherein said sensor means for sensing vehicle deceleration is connectedwith a portion of the vehicle spaced apart from said first vehicle seatand from said second vehicle seat, said RF transmitter being disposed ata location in the vehicle spaced apart from said first seat and fromsaid second seat.
 9. A vehicle safety apparatus as set forth in claim 8wherein:said first locking means comprises a first locking membermovable between a first position in which said first spool is free torotate in the first belt withdrawal direction and a second position inwhich said first spool is blocked from rotation in the first beltwithdrawal direction, and first electromagnet means disposed adjacent tosaid first locking member and electrically connected with said first RFreceiver means and energizeable in response to the first output signalfor moving said first locking member between its first and secondpositions; and said second locking means comprises a second lockingmember movable between a first position in which said second spool isfree to rotate in the second belt withdrawal direction and a secondposition in which said second spool is blocked from rotation in thesecond belt withdrawal direction, and second electromagnet meansdisposed adjacent to said second locking member and electricallyconnected with said second RF receiver means and energizeable inresponse to the second output signal for moving said second lockingmember between its first and second positions.
 10. A vehicle safetyapparatus comprising:a seat for an occupant of a vehicle; vehicleoccupant protection means connected with said seat and responsive to anelectrical signal for restraining movement of an occupant of said seatrelative to said seat in response to vehicle deceleration exceeding apredetermined deceleration; means for connecting said vehicle occupantprotection means with said seat; sensor means for sensing vehicledeceleration exceeding a predetermined deceleration and for providing acontrol signal indicative thereof; an RF transmitter electricallyconnected with said sensor means and actuatable in response to thecontrol signal to transmit an RF signal; and RF receiver means connectedwith said seat for receiving the RF signal and for providing an outputsignal indicative of the RF signal, said vehicle occupant protectionmeans being actuatable in response to the output signal for restrainingmovement of the vehicle occupant relative to said seat.
 11. A vehiclesafety apparatus comprising:a seat for an occupant of a vehicle; vehicleoccupant protection means on said seat and responsive to an electricalsignal for protecting a vehicle occupant in response to vehicledeceleration exceeding a predetermined deceleration; a battery mountedon said seat for supplying electric power to actuate said vehicleoccupant protection means; a piezoelectric member associated with thevehicle seat and responsive to an occupant sitting on the seat forgenerating an electric current; and means for electrically connectingsaid piezoelectric member with said battery to charge said battery withthe electric current generated by said piezoelectric member.
 12. Avehicle safety apparatus as set forth in claim 11 wherein saidpiezoelectric member is disposed in a seat bottom cushion of the vehicleseat and is deformable in response to an occupant sitting on the seatfor generating an electric current to charge said battery.
 13. A vehiclesafety apparatus as set forth in claim 11 further comprising sensormeans on said vehicle seat for sensing vehicle deceleration exceeding apredetermined deceleration, said sensor means upon the occurrence ofvehicle deceleration exceeding a predetermined deceleration electricallyinterconnecting said battery and said vehicle occupant protection meansthereby to actuate said vehicle occupant protection means.
 14. A vehiclesafety apparatus comprising:a seat for an occupant of a vehicle; vehicleoccupant protection means on said seat and responsive to an electriccurrent for protecting a vehicle occupant in response to vehicledeceleration exceeding a predetermined deceleration; sensor means forsensing vehicle deceleration exceeding a predetermined deceleration andfor providing an electrical control signal indicative thereof; and abattery mounted on said vehicle seat for supplying electric current toactuate said vehicle occupant protection means in response to saidsensor means providing said electrical control signal; wherein saidsensor means for sensing vehicle deceleration is fixedly connected witha portion of the vehicle spaced apart from the vehicle seat, and furthercomprising (i) an RF transmitter electrically connected with said sensormeans and actuatable in response to the sensor means control signal totransmit an RF signal and (ii) an RF receiver for receiving the RFsignal and for providing an output signal indicative thereof, saidvehicle occupant protection means being actuatable in response to saidoutput signal for protecting the vehicle occupant.
 15. A vehicle safetyapparatus set forth in claim 14 wherein said RF receiver is mounted onsaid vehicle seat and is powered by said battery.
 16. A vehicle safetyapparatus comprising:a seat for an occupant of a vehicle; vehicleoccupant protection means on said seat and responsive to an electricalsignal for protecting a vehicle occupant in response to vehicledeceleration exceeding a predetermined deceleration; a battery mountedon said seat for supplying electric power to actuate said vehicleoccupant protection means; a piezoelectric member associated with thevehicle seat and responsive to an occupant sitting on the seat forgenerating an electric current; and means for electrically connectingsaid piezoelectric member with said battery to charge said battery withthe electric current generated by said piezoelectric member; whereinsaid vehicle occupant protection means comprises a seat belt retractorhaving a spool on which belt webbing is wound and which is rotatable ina belt withdrawal direction and an opposite belt retraction directionand a locking means for blocking rotation of said spool in the beltwithdrawal direction in response to an electrical signal.
 17. A vehiclesafety apparatus as set forth in claim 16 wherein said retractor lockingmeans comprises a locking member movable between a first position inwhich said spool is free to rotate in the belt withdrawal direction anda second position in which said spool is blocked from rotation in thebelt withdrawal direction and electromagnet means disposed adjacent tosaid locking member and electrically connected with said battery andenergizeable by said battery for moving said locking member between itsfirst and second positions.
 18. A vehicle safety apparatus as set forthin claim 17 comprising an intermediate linkage operatively disposedbetween said locking member and said retractor spool, said lockingmember acting through said intermediate linkage to block rotation ofsaid spool in the belt withdrawal direction upon movement of saidlocking member into the second position.
 19. A vehicle safety apparatuscomprising:a seat for an occupant of a vehicle; vehicle occupantprotection means on said seat and responsive to an electrical signal forprotecting a vehicle occupant in response to vehicle decelerationexceeding a predetermined deceleration; a battery mounted on said seatfor supplying electric power to actuate said vehicle occupant protectionmeans; a piezoelectric member associated with the vehicle seat andresponsive to an occupant sitting on the seat for generating an electriccurrent; means for electrically connecting said piezoelectric memberwith said battery to charge said battery with the electric currentgenerated by said piezoelectric member; sensor means on said vehicle ata location remote from said vehicle seat for sensing vehicledeceleration exceeding a predetermined deceleration and for providing acontrol signal indicative thereof; an RF transmitter electricallyconnected with said sensor means and actuatable in response to thecontrol signal to transmit an RF signal; and RF receiver means on saidvehicle seat for receiving the RF signal and for providing an electricalsignal indicative of the RF signal to said vehicle occupant protectionmeans to actuate said vehicle occupant protection means.